Molecular nutrition and toxicology is actually fairly difficult, particularly when it comes to long-term/subtle effects.
And we're not just talking nutrition anyway. We're talking ecology, we're talking intellectual property rights, and we're talking the ethics of making strains of plants that are resistant to the type of herbicide you just happen to sell yourself.
See above. More work has been done on molecular toxicology due to genetic engineering being used, not the other way around. There will never be an end to it - we simply don't know everything about the regular food we eat to begin with, as evidenced by the thousands of studies and news articles on the effects (long term and otherwise) of consuming different plants in different quantities. I argue that, more likely than not, if a vegetable with a protein from a type of fish doesn't kill pigs, pass human trials with the same results, and can feed millions of people in poor-quality agricultural land, it's about as safe to put in Walmart as a kohlrabi or a star-fruit. I guarantee you people living with drought conditions aren't going to be worrying about any slightly increased risk of whatever if they can feed their families come winter.
It's definitely possible to misapply genetic engineering. I simply hate it when people say it should be banned without considering the enormous benefits, simply because of the unethical actions of one or two corporations. It runs parallel with the nuclear power scare. I don't want to see development in this area stunted to the degree that fission has been. I
do want to see viability studies for cross-species pollination, use of crops in areas that do not have wild cousins in the immediate vicinity, introduced herbicide
vulnerabilities for control, consideration for seed dispersal methods (i.e, let's not make fast-growing Antarctic-hardy varieties of thistle FFS), etc. etc.